1. Field of the Invention
The present invention relates to a code division multiple access (hereinafter, referred to as "CDMA") mobile communication system, and more particularly to a device and method for automatically, precisely controlling transmission power of a CDMA site.
2. Description of the Related Art
In a CDMA mobile communication system, communication capability for a frequency resource is determined by noise distributions between whole cells which use the same frequency band. Therefore, in order to optimize the communication capability for the whole cells, the high frequency output transmitted from the cells must be controlled appropriately. Thus, it is necessary to control the high frequency transmission power precisely; controlling the high frequency transmission power is, however, difficult due to the differences between the features of analog circuit and digital transmission circuit of a transmitter in a CDMA site.
A conventional CDMA mobile communication system has a transmission circuit consisting of inconsistent analog and high frequency circuits. Therefore, in the CDMA system which requires for a precise transmission power, the transmission power is controlled by measuring the transmission power and adjusting gains of variable circuits according thereto. To the end, variable gain sections of the circuit boards are precisely adjusted at the manufacturing process, or the high frequency circuit and analog circuit are manually adjusted upon measuring the whole transmission power when setting up the sites. Such conventional method requires expert technical knowledge and lot of time for controlling the transmission power precisely.